Portable refrigerator



FIG. 1 is a perspective view of a portable refrigerator showing my new design with the lid closed;

FIG. 2 is another perspective view thereof;

FIG. 3 is another perspective view of the portable refrigerator of FIG. 1 with the lid open;

FIG. 4 a front elevational view thereof;

FIG. 5 a rear elevational view thereof;

FIG. 6 a left side view thereof;

FIG. 7 is a right side view thereof;

FIG. 8 is a top plan view thereof; and,

FIG. 9 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the portable refrigerator that form no part of the claim. 

CLAIM The ornamental design for a portable refrigerator, as shown and described. 